-The following table provides another view of the same information:
-
-@multitable {Missing values in excluded categories} {@code{VALIDN}} {other} {@code{TOTALN}}
-@headitem @tab @code{VALIDN} @tab other @tab @code{TOTALN}
-@item Valid values in included categories @tab yes @tab yes @tab yes
-@item Missing values in included categories @tab --- @tab yes @tab yes
-@item Missing values in excluded categories @tab --- @tab --- @tab yes
-@item Valid values in excluded categories @tab --- @tab --- @tab ---
+For categorical variables, system-missing values are never in included
+categories. For scale variables, there is no notion of included and
+excluded categories, so all values are effectively included.
+
+The following table provides another view of the above rules:
+
+@multitable {@w{ }@w{ }@w{ }@w{ }Missing values in excluded categories} {@t{VALIDN}} {other} {@t{TOTALN}}
+@headitem @tab @t{VALIDN} @tab other @tab @t{TOTALN}
+@item @headitemfont{Categorical variables:}
+@item @w{ }@w{ }@w{ }@w{ }Valid values in included categories @tab yes @tab yes @tab yes
+@item @w{ }@w{ }@w{ }@w{ }Missing values in included categories @tab --- @tab yes @tab yes
+@item @w{ }@w{ }@w{ }@w{ }Missing values in excluded categories @tab --- @tab --- @tab yes
+@item @w{ }@w{ }@w{ }@w{ }Valid values in excluded categories @tab --- @tab --- @tab ---
+@item @headitemfont{Scale variables:}
+@item @w{ }@w{ }@w{ }@w{ }Valid values @tab yes @tab yes @tab yes
+@item @w{ }@w{ }@w{ }@w{ }User- or system-missing values @tab --- @tab yes @tab yes